PSLE Usha had a basket of blue marbles and yellow marbles in the ratio 17 : 8. She removed an equal number of blue marbles and yellow marbles from the basket. The ratio of the number of blue marbles and yellow marbles left in the basket became 3 : 1. What percentage of the marbles were left in the basket?
|
Blue marbles |
Yellow marbles |
Difference |
Total |
Before |
17x2 = 34 u |
8x2 = 16 u |
9x2 = 18 u |
25x2 = 50 u |
Change |
- 7 u |
- 7 u |
|
|
After |
3x9 = 27 u |
1x9 = 9 u |
2x9 = 18 u |
4x9 = 36 u |
When Usha removed an equal number of blue marbles and yellow marbles, the difference between the number of blue marbles and yellow marbles at first and in the end remains the same.
LCM of 9 and 2 is 18.
Percentage of the marbles left in the basket
=
3650 x 100%
= 1825 x 100%
= 72%
Answer: 72%